1. Field of the Invention
The present invention relates to methods for manufacturing organic EL (electroluminescence) devices. The organic EL devices can be used, for example, as a display of a television as well as a computer, and also as a light source such as a backlight of a liquid crystal display.
2. Description of Related Art
Recently, there has been an increasing trend toward portability of information terminals, along with the development of power saving displays, which becomes necessary to achieve portability. In particularly, attention has be given to organic EL displays that are light-emitting devices having a structure in which an organic light-emitting layer is provided between an anode and a cathode.
In a small-capacity display device or a monochrome organic EL device used as a backlight, for example, after an anode layer is formed on a substrate, a light-emitting layer (and a hole injection layer and/or a hole transport layer provided when necessary) is formed by a spin coating method in many cases. In addition, a cathode layer is formed on the light-emitting layer, for example, by a vacuum deposition method.
The organic EL device described above generally includes an organic EL panel and a driving circuit which are separately formed, along with an anode terminal as well as a cathode terminal that are provided for the organic EL panel. By connecting these terminals to front ends of wires extending from the driving circuit, a voltage is applied between the anode and the cathode.
Conventionally, the formation of the cathode terminal has been performed by the following methods. The first method is a method that a part of each cathode layer uses as a cathode terminal. In other words, front ends of wires extending from a driving circuit are brought into direct contact with the cathode layer and then fixed. In a second method a cathode terminal is formed of a conductive paste on the cathode layer. In a third method a cathode terminal is formed on a substrate at the same time that anode is formed. In this case, after the step described above, a light-emitting layer is formed over the entire surface of a substrate, and the light-emitting layer is partly removed so that the cathode terminal is exposed. A cathode layer is then formed so as to cover the cathode terminal. However, the above methods have the problems described below.
In the first method, since the cathode layer of the organic EL device is formed of an unstable material in many cases, there is a risk that the cathode terminal may be oxidized. In the second method, there is a risk that the cathode may corrode due to a solvent of the conductive paste. In the third method, the step of partly removing the light-emitting layer so as to expose the terminal for the cathode is complicated, and in addition, there is a risk that superior electric connection to the cathode layer may not be obtained at the side surface of the light-emitting layer or the like which is formed by the partial removal thereof.
The present invention provides a method for manufacturing an organic EL device in which at least a first electrode layer, a light-emitting layer, and a second electrode layer are sequentially formed on a substrate. The method for manufacturing the organic EL device can include a step of forming the first electrode layer, a first terminal connected to the first electrode layer, and a second terminal to be connected to the second electrode layer on the substrate, a step of forming the light-emitting layer so as to cover at least the first electrode layer and the second terminal, a step of providing a conductive material penetrating the light-ermtting layer so as to be electrically connected to the secnd terminal, and a step of forming the second eelectrode layer so as to be electrically connected to the conductive material.
The present invention also provides a method for manufacturing an organic EL device in which at least a first electrode layer, a light-emitting layer, and a second electrode layer are sequentially formed on a substrate. The method for manufacturing the organic EL device described above can include a step of forming the first electrode layer, a first terminal for the first electrode layer, and a second terminal for the second electrode layer on the substrate, a step of forming the light-emitting layer so as to cover at least the first electrode layer and the second terminal, a step of supplying a liquid containing a solvent that dissolves the light-emitting layer and a conductive material to a position on the light-emitting layer corresponding to the second terminal so as to form a throughhole which extends to the second terminal, in the light-emitting layer using the solventr so-that the liquid remains in the throughhole, a step of removing the solvent remaining in the throughhole so as to fill the throughhole with the conductive material, and a step of forming the second electrode layer so as to be electrically connected to the conductive material and so as to cover a position at which the throughhole is provided.
The present invention also provides a method for manufacturing an organic EL device in which at least a first electrode layer, a light-emitting layer, and a second electrode layer are sequentially formed on a substrate. The method for manufacturing the organic EL device described above can include a step of forming the first electrode layer, a first terminal for the first electrode layer, and a second terminal for the second electrode layer on the substrate, a step of forming the light-emitting layer so as to cover at least the first electrode layer and the second terminal, a step of supplying a liquid containing a volatile solvent that dissolves the light-emitting layer and a conductive material to a position on the light-emitting layer corresponding to the second terminal so as to form a throughhole, which extends to the second terminal, in the light-emitting layer using the volatile solvent, and removing the volatile solvent so as to fill the throughhole with the conductive material, and a step of forming the second electrode layer at a position at which the throughhole is provided so as to be electrically connected to the conductive material.
The present invention provides an organic EL device including at least a first electrode layer, a light-emitting layer, and a second electrode layer provided in that order on a substrate. In the organic EL device, a first terminal connected to the first electrode layer and a second terminal for the second electrode layer are formed on the same surface as that on which the first electrode layer is provided, and the second terminal and the second electrode layer are in electrical contact with each other through a conductive material penetrating the layer rovided therebetween.
The present invention provides an electronic apparatus including an organic EL device. The organic EL device comprises at least a first electrode layer, a light-emitting layer, and a second electrode layer in that order on a substrate, wherein a first terminal connected to the first electrode layer and a second terminal for the second electrode layer are formed on the same surface of the substrate as that on which the first electrode layer is provided, and the second terminal and the second electde layer are in electrical contact with each other through a conductive material penetrating the layer provided therebetween.